Red vat dye and process of making same.



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GADIENT ENGI, OF BASEL, SWITZERLAND, ASSIGNOR TO SOCIETY OF CHEMICAL INDUSTRY IN BASLE, OF BASEL, SWITZERLAND.

RED VAT DYE AND PROCESS OF MAKING SAME.

Specification of Letters Patent.

Application filed July 18, 1908.

Patented June 8, 1909.

Serial No. 444,264.

To all whom it may concern:

Be it known that I, GADIENT ENeI, doctor of philosophy and chemist, a citizen of the Swiss Republic, and resident of Basel, Switzerland, have invented new and useful Red Vat Dyestuffs and a Process of Making Same, of which the following is a full, clear, and exact specification.

In the United States Letters Patent No. 841003 dated January 8th, 1907 is described a yellow-red vat-dyestufl' by heating salicylthioacetic acid (phenylthioglycolorthocarboxylic acid) with an aromatic nitrohydrocarbon in presence of isatin.

I have found that the derivatives of isatin, acidylated at the nitrogen, as for instance acetylisatin NOO.CH3

can also be condensed with 3 oxy- 1 -thionaphthene to an acidylderivative of the dyestuff described in the said Letters Patent No. 841003, which acidylderivative constitutes, like the not acidylated corresponding dyestufi, a dye suitable to dye animal and vegetable fibers in an alkaline vat. In this reaction the 3-oxy-1-thidnaphthene can be replaced by one of its products of substitution or the oxythionaphthene-compound can be produced in the reaction mass itself by heating phenylthio glycol-ortho-carboxylic acid or its products of substitution with the acidylisatin employed, in presence of a condensing agent capable of transforming the phenylthioglycol-ortho-carboxylic acid or its products of substitution intermediary into the corresponding oxythionaphthene-compound.

The invention will be illustrated by the following examples.

Example I: 12.6 parts of acetylisatin (obtained by heating isatin with acetic anhydrid) are boiled together with 10 parts of 3-oxy-1-thionaphthene and 100 parts of alcohol for 2 to 3 hours on a water bath in an apparatus with a reflux condenser. After cooling, the crystallized dyestuif is separated by filtration, washed with alcohol and dried. It is thus obtained in the form of well formed, brilliant red needles melting at 253 to 255 C. In cold benzene or cold nitrobenzene the dyestuff is diflicultly soluble but it is easily soluble in hot benzene or hot nitrohenzene to yellow-red solutions. With concentrated sulfuric acid it gives a dirtybrown solution. On treating the dyestufl with soda lye and hydrosulfite it yields a yellow vat dyeing cotton bright, yellowishred tints fast to washing, to light and to chlorin. Instead of starting from oxythionaphthene the phenyl-thioglycol-ortho-carboxylic acid may be employed as starting material and the transformation of this latter into oxythionaphthene and the condensation of the resulting oxythionaphthene with acetyl-isatin thus be joined in a sole operation.

Example II: 21.2 parts of phenylthioglycol-ortho-carboxylic acid are boiled with 19 parts of acetylisatin and 100 parts of acetic anhydrid for 2 to 3 hours on an oil bath. After a short timerthe condensation takes place, the dyestuff being precipitated. After cooling, the mass of reaction constitutes a thick paste from which the dyestuff is separated by filtration, washing with alcohol and drying. In a similar manner is effected the preparation of dyestuffs with other acidylderivatives of isatin and with products of substitution of the henylthioglycol-orthocarboxylic acid or of the oxythionaphthene, as for instance their halogenderivatives.

What I claim is:

1. The described process for the manufacture of red vat-dyestuffs by condensing one molecule of an acidyl-derivative of isatin with one molecule of an oxythionaphthenecompound.

2. The described process for the manufacture of red vat-dyestuffs by boiling one molecule of a derivative of phenylthioglycolortho carboxylic acid with one molecule of an acidyl-derivative of isatin, in presence of a condensing agent capable of transforming the phenylthiogl-ycol-ortho-carboxylic acid derivative intermediary into the corresponding oxythionaphthene-compound.

3. As new articles of manufacture, the vatdyestuifs, which can be obtained by condensing an acidyl-derivative of isatin with an oxythionaphthene-compound, being only diffieultly soluble in cold alcohol and benzene, more easily soluble in hot benzene and nitrobenzene, soluble in concentrated sulfuric acid with a dirty-lorown coloration and yielding on treatment With alkaline reducing agents yellowish vats, from which vats uninordanted cotton is dyed in red shades, fast to Washing, light and ehlorin.

In witness whereof I have hereunto si ned a my name this ninth day of July 1908, in the l 0 presence oi two eubscribing \YIUICSSQS.

GADIEN'I ENGI.

\Vitnesses GEO. GIFFORD, ERNST Hamill. 

